There is a widely documented need for tactile area sensors to provide a sense of feel for computer controlled robots and programmed assembly machines. This type of sensor can be used for object identification as well as for insertion and mating tasks associated with assembly. The preferred location of the sensor is on the extremity of a movable finger. Consequently, the sensor must be compact and rugged and capable of being interrogated with a minimum of communication channels to the system computer. In addition, the sensor must be low cost, have good stability, and provide resolutions of better than one hundred bits per square inch to be compatible with industrial applications.
Many concepts for tactile area sensors have been proposed, but with the exception of low density sensors based on guided rods or force activated switches, most have not been reduced to practice. Those concepts based on resistance change of conductive rubber, graphite filled foam, or carbon fibers have the potential for low cost, durable sensors; however, technical problems have not been solved. Concepts based on arrays of conventional pressure sensors are technically feasible but the cost is prohibitive.